Studies On Genetic Diversity Of Potato (S.tuberosum L.) Germplasm Resources

Potato is a nutritious crop cultivated over the world. Because potato is an agamogenesis autotetraploid crop with complex genetics, germplasm resources are the basic materials of crop breeding, and play an important role in enhancing breeding efficency. The study on genetic diversity of potato germplasm resources is important for collection, conservation and utilization of the resources.Morphologic and SRAP (Sequence-related Amplified Polymorphism) molecular markers were used to study the genetic diversity and the blood relationships of the potato resources through coefficient of variation, cluster and relevancy analysis, and the breeding application of these resources was evaluated according to different target traits. The main results are as following:The analysis based on variation coefficient showed that the different traits had different coefficient, and the average variation coefficient of 33 traits was 95.6% ranging from 1.8 to 463.6%. The cluster analysis based on the morphologic traits showed that 44 varieties were classified into 4 main groups as the genetic distance was 9.32, and the first main group could be classified into different subgroups. Meanwhile, the traits including disease resistances, qualities, yield and appearances were great different among the groups. The results indicated the genetic diversity of these resources were much abundant.23 out of the 27 primer pairs random selected were polymorphic among the 44 varieties, the polymorphism ratio of primers was 63.9%, and 104 polymorphism bands were obtained, and the mean of the polymorphism bands was 4.5. These results demonstrated that SRAP had much higher polymorphism in the tested potato recourses. Based on the cluster analysis according to the SRAP makers, the genetic distance of the different varieties was from 0.147 to 0.741. As the genetic distance was 0.67, 44 varieties were classified into 4 main groups, which included one complex group and 3 independent ones, and the complex group could be classified into 7 subgroups. So the...